Cranking means



March 23, 1965 z. A. WACHTA 3,174,358

CRANKING MEANS Filed March 20, 1963 515.4 its? $53 iga United States Patent 3,174,358 CRANKING MEANS Zygmunt A. Wachta, Boston, Mass, assignor to Allis- Chalmers Manufacturing Company, Milwaukee, Wis. Filed Mar. 20, 1963, Ser. No. 266,740 6 Claims. (Cl. 74-548) This invention relates generally to cranking means. More particularly, it rel-ates to a type of crank which is rotatable in opposite directions but effects rotation of an associated shaft only when rotated in a predetermined direction.

A crank incorporating the present invention is particularly well suited for manually operating electric circuit breaker contacts but is not necessarily limited to such application. In some circuit breakers, for example, the contacts are opened and closed by operation of an electric motor. The motor rotates in one direction to drive a cam and it is the cam position that determines whether the contacts are open or closed. Sometime a crank is employed to drive the cam when the motor is not in operation. But since accidental rotation of the cam in the wrong direction can result in mechanical damage to the circuit breaker mechanism, it is important that the crank be able to effect rotation of the cam only in the same direction as the motor. More specifically, the crank should effect cam rotation only when rotated in the proper direction and not otherwise. Such a crank is an important but infrequently used device and it is desirable, therefore, that it be reliable and foolproof but not costly to fabricate. One-way cranks of various types are, of course, well known. Ratchet and pawl type cranks, for example, could perform the above described function but such cranks are relatively complicated and expensive to fabricate since they do not usually employ standard or readily available hardware.

It is an object of the present inventionto provide an improved crankfor rotating an associated shaft.

Another object is to provide an improved crank which is rotatable in either direction but effects rotation of an associated shaft only when rotated in a predetermined direction.

Another object of this invention is to provide an improved crank of the aforesaid character which employs the principle of the inclined plane.

Another object is to provide an improved crank of the aforesaid character which can be constructed of readily available standard, low cost components and does not require precision machining in its fabrication.

Another object is to provide an improved crank of the aforesaid character which is particularly adapted for manually operating circuit breaker contacts.

The accompanying drawing illustrates preferred embodiments of the invention but it is to be understood that the embodiments illustrated are susceptible to modifications with respect to details thereof without departing from the scope of the appended claims.

In the drawing:

FIG. 1 is an elevational view of a crank incorporating the present invention shown in association with the drive shaft and gear reduction unit for operating circuit breaker contacts;

FIG. 2 is an enlarged side view of the drive shaft shown in FIG. 1;

FIG. 3 is an enlarged view, partly in section, of the end of the crank shown in FIG. 1 and shows components of the crank'in one position;

FIG. 4 is an end view of the components of the crank shown in FIG. 3;

3,174,358 Patented Mar. 23, 1965 FIG. 5 is a view similar to FIG. 3 but showing the components of the crank in another position and associated with the aforesaid drive shaft; and

FIG. 6 is a view, partly in section, of the end of another embodiment of the invention.

Referring to FIG. 1 of the drawing, the numeral 10 designates a crank constructed in accordance with the present invention. For purposes of illustration, crank 10 is shown associated with the drive shaft 20 of a reduction gear unit 12. Reduction gear unit 12 has an output shaft 14 which is understood to rotate in the direction of an arrow 16 to move circuit breaker contacts (not shown) to open and closed positions. Output shaft 14 is normally rotated by an electric motor 18 which is as.- sociated with drive shaft 20 of reduction gear unit 12. However, when motor 18 is deenergized, output shaft 14 is adapted to be rotated in response to manual rotation of a drive shaft 20 which projects from reduction gear gear unit 12 is provided with crank engagement means to adapt it for rotation by a crank. Preferably, the crank engagement means take the form of a cylindrical pin 24 which is force fitted in a hole near the end of cylindrical drive shaft 20 and has its ends extending from the sides of the shaft. This type of construction is relatively simple and economical in keeping with the objects of the present invention. However, integrally formed projections, slots or other means could be provided on shaft 20 to serve as crank engagement means.

As'FIGS. l, 3, 4 and 5 show, crank 10 comprises a driving member 26 and a driven member 28. Driving member 26 is a rigid member preferably fabricated of readily obtainable cylindrical metal stock. To adapt it for easy manual operation by a human operator, driving member 26 has the U-shaped configuration shown in FIG. 1. If preferred, however, driving member 26 could be a straight shaft rotatable by suitable mechanical means.

FIGS. 3 and 4 show that driving member 26 is provided near its end with a driving device or look washer 30 which is rigidly secured thereto as by welding at 32. Driving washer 30 preferably is a well known type of lock washer which is splitso as to provide ends which are forced out of registry thereby forming a helix. In the embodiment shown, driving washer 30 has a slipping surface 34 which defines a left helicoid andhasan engaging end face 36.

Driven member 28 is a rigid member, preferably fabricated ofcylindrical metal stock, and is hollow so as to be adapted to fit concentrically over-the end of driving member 26 and its driving washer 3G. Driven member 28 is provided with a driven device or washer 38 :which is rigidly secured thereto in the hollow interior as by welding at 40. Driven washer 38 is similarin all respects to driving Washer 39, hereinbefore described, and has a slipping surface 42 andan engaging end face 44. For

convenience in fabrication, the interior of driven memspring 50. Preferably, the internal diameter of the washers 30 and 38 should be only slightly larger than the diameter of driving member 26 so that slack or play between the driving member 26 and driven member 28 is reduced to a minimum.

Driven member 28 is provided with means for cooperating with the crank engagement means on drive shaft 20 of reduction gear unit 12. Thus, driven member 28 has a pair of oppositely disposed slots 48 at one end which are adapted to accommodate the projecting ends of pin 24 when the driven member is disposed on drive shaft 20 of reduction gear unit 12, as FIGS. 1 and 5 show. As FIG. 5 shows, the slots 48 are sufficiently long so that reciprocating motion of driven member 28 which accompanies rotation in the wrong direction is not inhibited by pin 24.

Biasing means are provided which act on driving member 26 and driven member 28 and tend to urge the washers 38 and 30 into engagement. The biasing means take the form of a helically shaped compression spring 50 which is disposed within driven member 28 around driving member 26 and bears against driving washer 30 and against engagement means such as a plate 52 which is rigidly secured as by welding at 54 to the end of driven member 28. Plate 52 is preferably a Well known type of flat washer of suitable size. Spring 50 acts against plate 52 and thus tends to move driven member 28 and thus its driven washer 38 against driving washer 30.

If preferred, instead of employing plate 52, driven member 28 could be provided with engagement means such as an integrally formed projection (not shown) against which spring 50 could bear. However, such construction would require a more costly machining operation.

During assembly, plate 52 and then spring 50 are slid onto driving member 26. Washer 38 is then disposed on driving member 26 and welded in place. Then, driven member 28, with its washer 38 in place, is disposed over the end of driving member 26 and plate 52 is welded to driven member 28.

Crank operates as follows. Assume that driven member 28 of crank 10 is associated with the crank engaging means on drive shaft as shown in FIG. 1. Rotation of driving member 26 in the direction of an arrow 56 shown in FIG. 3 (i.e., the wrong direction as regards the embodiment disclosed) does not effect corresponding rotation of driven member 28 because surface 34 of driving washer 30 slips against surface 42 of driven washer 3S and the end faces 36 and 44 of the washer 30 and 38, respectively, do not come into abutting engagement. Such slippage is possible because of the resiliency of spring 59 and is accompanied by recipro i eating motion of driven member 28. However, upon rotation of driving member 26 in the direction of arrow 22 shown in FIGS. 1 and 5 (i.e., the correct direction as regards the embodiment disclosed) spring 50 urges the washers 30 and 38 together so that their surfaces 34 and 42, respectively, eventually mate as shown in FIG. 5 and end face 36 of driving washer 30 pushes against end face 44 of driven washer 33 as driving member 26 is rotated. This causes driven member 28 to rotate in correspondence with driving member 26 and to effect rotation of drive shaft 20 of reduction gear unit 12.

It is apparent that to provide a crank which is constructed as crank 10 but which is adapted to effect rotation in the opposite direction, the washers 30 and 38 which define left helicoids should be replaced by washers which define right helicoids.

Referring to FIG. 6, the numeral 69 designates a crank which incorporates the present invention but which is adapted to effect rotation in the opposite direction to that of crank 10 hereinbefore described. Crank 60 differs from crank 10 as follows. In crank 60, driving device or lock washer 30 is secured to driving member 26 a short distance away from the end thereof. Driven device or lock washer 38 is located below washer 30 and is secured to driven member 28 as by welding at 62. Spring is disposed between shoulder 46 of driven member 28 and washer 30. Crank does not, therefore, require a plate such as plate 52 in crank 10. The washers 3t) and 38 in crank 60 are identical to those used in crank 10 but because of the manner in which employed in crank 60, driven member 28 rotates only when driving member 26 is rotated in the direction of an arrow 64 shown in FIG. 6. As will be understood, spring 50 is an expansion type spring and tends to force driven member 28 upwardly (with respect to FIG. 6) so that washer 38 engages washer 30.

Having now particularly ascertained and described the nature of my said invention and the manner in which it is to be performed, I declare that what I claim is:

1. In a crank for rotating an associated shaft in a predetermined direction, in combination,

a driving member,

a driving washer rigidly secured to said driving member, said driving washer comprising a split ring having its ends coplanar with the axis of said driving member and axially spaced therealong,

a driven member having means to engage and transmit torque to said associated shaft,

a driven washer rigidly secured to said driven member, said driven washer comprising a split ring having its ends coplanar with the axis of said driven member and axially spaced therealong, each of said washers formed as a helix of the same hand,

and means for urging said driving Washer into engagement with said driven washer so that one offset end of the driving washer abuts an offset end of the driven washer when said driving member is rotated in said predetermined direction to effect corresponding rotation of said driven member.

2. In a crank for rotating an associated shaft in a predetermined direction, said shaft having crank engaging means thereon, in combination,

a driving member,

a first lock washer rigidly secured around said driving member, said first lock washer being of the split ring type and having its ends coplanar with the axis of said driving member and axially spaced therealong,

a hollow driven member disposed around said one end of said driving member and said lock washer,

said driven member having a shoulder therewithin and having means to engage said crank engaging means on said associated shaft to transmit torque to said shaft,

a second lock washer rigidly secured within said driven member and disposed around said driving member, said second lock washer being of the split ring type and having its ends coplanar with the axis of said driving member and axially spaced therealong, each of said lock washers formed as a helix of the same hand, so that one end of the first lock washer abuts an offset end of the second lock washer,

and a compression spring disposed around said driving member and bearing against said first lock washer and against said shoulder within said driven member.

3. The combination according to claim 1 wherein said driven member is hollow and surrounds a portion of said driving member and said driving Washer, wherein said driven washer is secured within said driven member, and wherein said urging means comprises biasing means disposed within said driven member for acting upon said driving member and said driven member to effect engagement of said washers.

4. The combination according to claim 3 wherein said biasing means comprises a compression spring disposed around said driving member and bearing against said driving washer and against means provided on said driven member.

5. The combination according to claim 4 wherein said 3,174,358 5 6 means provided on said driven member comprises a plate References Cited by the Examiner connected on one end of said driven member. UNITED STATES PATENTS 6. The combination according to claim 3 wherein said 982 886 1/11 Servatius 8158 3 associated shaft has at least one projection thereon and 13283087 1/20 La Chot wherein said driven member has at 1ea st one slot in one 5 1,608,538 11/26 Wehmeier 74 548 end thereof for engaging said PIOJGCUOII on said shaft to effect transmission of torque to said shaft as said driven BROUGHTON DURHAM, Primary Examinamember rotates. MILTON KAUFMAN, Examiner. 

1. IN A CRANK FOR ROTATING AN ASSOCIATED SHAFT IN A PREDETERMINED DIRECTION, IN COMBINATION, A DRIVING MEMBER, A DRIVING WASHER RIGIDLY SECURED TO SAID DRIVING MEMBER, SAID DRIVING WASHER COMPRISING A SPLIT RING HAVING ITS END COPLANAR WITH THE AXIS OF SAID DRIVING MEMBER AND AXIALLY SPACED THEREALONG, A DRIVEN MEMBER HAVING MEANS TO ENGAGE AND TRANSMIT TORQUE TO SAID ASSOCIATED SHAFT, A DRIVEN WASHER RIGIDLY SECURED TO SAID DRIVEN MEMBER, SAID DRIVEN WASHER COMPRISING A SPLIT RING HAVING ITS ENDS COPLANAR WITH THE AXIS OF SAID DRIVEN MEMBER AND AXIALLY SPACED THEREALONG, EACH OF SAID WASHERS FORMED AS A HELIX OF THE SAME HAND, AND MEANS FOR URGING SAID DRIVING WASHER INTO ENGAGEMENT WITH SAID DRIVEN WASHER SO THAT ONE OFFSET END OF THE DRIVING WASHER ABUTS ON OFFSET END OF THE DRIVEN WASHER WHEN SAID DRIVING MEMBER IS ROTATED IN SAID PREDETERMINED DIRECTION TO EFFECT CORRESPONING ROTATION OF SAID DRIVEN MEMBER. 